	US 11,703,134 B2
	Metering valve with mid-stroke shutoff
Aaron F. Rickis, Longmeadow, MA (US); Lukasz Burek, Portland, CT (US); Sachin Ramprashad, West Hartford, CT (US); Steve Doerner, Enfield, CT (US); and Wayne S. Johnson, Jr., West Hartford, CT (US)
Assigned to Hamilton Sundstrand Corporation, Charlotte, NC (US)
Filed by Hamilton Sundstrand Corporation, Charlotte, NC (US)
Filed on Aug. 20, 2021, as Appl. No. 17/408,212.
Prior Publication US 2023/0058118 A1, Feb. 23, 2023
Int. Cl. F16K 11/07 (2006.01); F02C 7/232 (2006.01); F02C 9/26 (2006.01); F16K 31/122 (2006.01)

CPC F16K 11/0708 (2013.01) [F02C 7/232 (2013.01); F02C 9/263 (2013.01); F16K 31/1221 (2013.01); F05D 2220/32 (2013.01)]

17 Claims

1. A fuel system for a gas turbine engine comprising:

a fuel pump configured to deliver fuel from a fuel tank to a heat exchanger;

a first branch leading to an engine metering valve to meter fuel heading to a combustor of the gas turbine engine;

a fluid line downstream of the heat exchanger to communicate the fuel to the first branch;

a second branch;

a shutoff valve comprising a sprint, a piston, and a rear chamber of the piston; and

a bypass metering valve having

a housing including a main inlet port, a second supply port through the housing, a main outlet port, and a failsafe inlet port, the second branch leading into the main inlet port; and

a spool having a main inlet orifice and an outlet orifice, a first end, and a second end, the spool movable within the housing,

a metering valve outlet line connected from the housing to a line leading to the shutoff valve, and

a second supply line in fluid communication with the rear chamber of the piston and the metering valve outlet line,

wherein the spring is configured to urge the piston of the shutoff valve to a shutoff position at which the shutoff valve blocks flow from the metering valve outlet line from reaching an outlet to the fuel tank,

wherein the spool is movable to a shutoff position at which the bypass metering valve blocks flow from the main inlet port and the failsafe inlet port from reaching the metering valve outlet line and additionally blocks flow from the second supply line from moving into the spool such that the shutoff valve is forced into the shutoff position by the spring,

wherein the spool is also movable to a metering position at which the main inlet port and the main inlet orifice in the spool are aligned and the outlet orifice in the spool is aligned with the main outlet port in the housing such that fluid can be metered to the shutoff valve and passed downstream to the fuel tank,

wherein in the shutoff position of the bypass metering valve, the first end of the spool is spaced from a first shoulder of the housing associated with the first end of the spool and the second end of the spool is spaced from a second shoulder of the housing associated with the second end of the spool, such that a first control chamber is defined between the first end of the spool and the first shoulder, and a second control chamber is defined between the second end of the spool and the second shoulder;

wherein the metering valve is movable to:

a first failsafe position at which:

the first end bottoms out on the first shoulder and the failsafe inlet port communicates with the main outlet orifice in the spool, and

a second failsafe position at which:

the second end bottoms out on the second shoulder and the failsafe inlet port communicates with the main inlet orifice.

2. A fluid flow system comprising:

a shutoff valve comprising a spring, a piston, and a rear chamber of the piston; and

a metering valve having:

a housing including a main inlet port, a second supply port through the housing, a main outlet port, and a failsafe inlet port; and

a spool having a main inlet orifice and an outlet orifice, a first end, and a second end, the spool movable within the housing,

a metering valve outlet line connected from the housing to a line leading to the shutoff valve, and

a second supply line in fluid communication with the rear chamber of the piston and to the metering valve outlet line, and

wherein the spool is movable to a shutoff position at which the metering valve blocks flow from the main inlet port and the failsafe inlet port from reaching the metering valve outlet line and additionally blocks flow from the second supply line from moving into the spool such that the shutoff valve is forced into the shutoff position by the spring,

wherein in the shutoff position of the metering valve, the first end of the spool is spaced from a first shoulder of the housing associated with the first end of the spool and the second end of the spool is spaced from a second shoulder of the housing associated with the second end of the spool, such that a first control chamber is defined between the first end of the spool and the first shoulder, and a second control chamber is defined between the second end of the spool and the second shoulder,

wherein the metering valve is movable to:

a first failsafe position at which:

the first end bottoms out on the first shoulder and the failsafe inlet port communicates a limited amount of fluid to the metering valve outlet line and to the shutoff valve, and

the second supply line is in fluid communication with a line passing downstream to the use such that a pressure on the rear chamber of the shutoff valve is lower than a pressure on a front face of the piston, and the shutoff valve will allow flow to the line leading to the use; and

a second failsafe position at which:

the second end bottoms out on the second shoulder and the failsafe inlet orifice communicates a limited amount of fluid to the metering valve outlet line and to the shutoff valve, and

the second supply line is in fluid communication with the line passing downstream to the use such that the pressure on the rear chamber of the shutoff valve is lower than the pressure on the front face of the piston and the shutoff valve will allow flow to the line leading to the use.